Improvement in core-lifters for annular rock-drills



G. FBISBEE.

Gore-Lifters for Annular Rock-Drills.

Patented Feb. 17'. i874.

E rll A O7/ f ////7///// UNITED STATES PATENT OEEIeEo lIDEON FBISBIJE, OF READING, PENNSYLVANIA.

IMPROVEMENT lN CORE-LIFTEFIS FOR ANNULAR ROCK-DRILLS.

Specification forming part of Letters Patent No. 147,492, dated February 17, 1874; application filed January 21, 1874.

To all whom 'it may concern:

Be it known that I, GIDEoN lIfnrsnEE7 of` which forms a part of this specification, and

in Which- Figure l is a section taken through the axis of the core-lifter and annular drill to Which it is attached; and Fig. 2 is a transverse section taken on the line w a', Fig. l.

rlhe same parts are denoted by the same letters in both figures.

`This invention consists in the combination of an exterior pipe or ring, constructed with a tapering recess in its inner surface, and aring or annular Wedge inserted into said recess, and which, as the drill advances, slides over the core, but is wedged against it by the withdrawal of the drill.

A in the drawing represents the Leschot annular diamond bit, screwed into the section B of pipe which contains the core-lifter, and which is in turn screwed into the core-barrel or into another section of pipe. C is a tapered recess in the interior of B. D is the core-lifter, consisting of a cut ring of steel sprung into the recess C. It is tapered outside to t said re' cess, and has projections` E E on its inner surface, between whichthe ring is filed thin so as to be elastic. These projections have small pieces of bort or carbon set in their faces to prevent them from bein g Worn by the rock.

In operation, as the bit excavates the rock, and the core enters D, the latter rst becomes stationary on the core, and is then forced over it by the shoulder of recess C, the tube B revolving round D twill the required depth is reached. When the drill-rod is Withdrawn, D is forced toward the small en'd of the recess, clamping the core more irmly as the tube B recedes, until it det-aches the core from the solid rock.

The bit may itselt1 be recessed, as above described, and the core-lifter inserted into it; but I prefer the arrangement shown, as it perA mits the same core-lifter to be used with different bits.

Instead of the thin ring with projections, an annular Wedge may be used, made in two pieces, fitting the tapered recess.

I/Vhat I claim as my invention, and desire to secure by Letters Patent of the. United States, is-

The combination, operating substantially as described, of an annular core-lifter and a tube or ring constructed with a tapering recess in its inner surface.

GrDEoN FEIsBEE.-

Iitnessesz SAMUEL GnRrsMAN, GEO. HADEsTY. 

